1. Field of the Invention
The present invention relates to
The present invention relates to an instrument for injecting an intraocular lens into an eye of a patient.
2. Description of Related Art
As one of operative treatments for cataract, generally used is a method of removing a crystalline lens from an eye of a patient and then injecting an intraocular lens in place of the crystalline lens. To inject the intraocular lens, the following steps are taken: first making an incision in an eyeball of a patient's eye; fragmenting and aspirating a clouded crystalline lens through the incision by for example an ultrasonic cataract-surgery device (a phaco-emulsification device); and then injecting the intraocular lens into the eye through the incision to implant it in place of the crystalline lens.
If a large incision is made, it may become a burden on the eyeball and also cause astigmatism of the patient's eye after the operation. To prevent such the disadvantages, an intraocular lens injecting instrument called an injector is used to inject a foldable intraocular lens into an eye through a smaller incision. In this injector, the foldable intraocular lens held in a housing of the injector is pushed toward the tip of the injector while being folded into a smaller shape. Thereafter, the intraocular lens is pushed out of the tip of the injector inserted in the eye through the incision and is spread (unfolded) in the eye.
Working pressure of the above injector to push out the intraocular lens (i.e., force needed to operate a push-out device) is fixed. Thus, the injector may often be hard to operate because some operators feel such fixed working pressure as too light (too low) or others feel it as too heavy (too high).